1. Technical Field
The present invention relates to a thermoelectric power generation system for a vehicle, and more particularly, to a thermoelectric power generation system for a vehicle that generates a temperature difference in a thermoelectric element using a vortex tube.
2. Description of the Related Art
A thermoelectric element is collectively known as an element that uses various effects generated by an interaction of heat and electricity. As the thermoelectric effect, there are a thermistor which is an element having a characteristic of a negative temperature coefficient in which electric resistance is reduced in proportion to an increase in temperature, an element using a Seebeck effect which is a phenomenon of generating an electromotive force due to a temperature difference, an element using a Peltier effect which is a phenomenon of generating absorption (or generation) of heat due to a current, and the like.
The Seebeck effect is one of the thermoelectric phenomena in which a current flows in a closed circuit which connects two metals or semiconductor when a temperature difference is generated between the two metals or the semiconductor. These phenomena will be described in more detail below.
When a temperature difference is given to both tips (e.g., both ends) A and B of one metal rod, an electromotive force based on a heat flow is generated between the A and B (e.g., is generated between each end of the metal rod). Since the electromotive force is different based on a metal type, when both tips A and B of two different metal types are bonded, a difference in electromotive force between both tips A and B of each metal is generated and thus a current flows in a circuit. When a middle section of a metal is cut, the difference in electromotive force of the two metal types appears at both cut tips. This is referred to as a thermoelectromotive force.
A thermoelectric couple used for temperature measurement uses the thermoelectromotive force. Thermoelectric power generation using the thermoelectromotive force uses the Seebeck effect in which when a temperature difference is given to both tips of a Seebeck element which is metal or semiconductor, a potential difference is generated between a heat source unit and a cooling unit and may directly convert heat into electricity without a mechanical driving unit. The thermoelectric power generation has energy generation efficiency which is proportional to the temperature difference between the heat source unit and the cooling unit, and therefore may not have substantially high energy generation efficiency when the temperature difference therebetween is minimal and may require separate energy for forming a condition in which the temperature difference is substantial.